3D Suspension Plasma Spraying (SPS) Coatings Build-up Simulation

In suspension plasma spraying (SPS), particle conditions upon impact i.e. trajectory, size, velocity, and temperature have an important influence on the structure of the coatings. To understand the SPS micro structure and predicting coating attributes such as porosity, columnar structure, thickness and surface roughness a three-dimensional predictive model for coating build-up on a flat substrate has been developed.

To develop the model, impact property values of each particle including size, velocity, temperature, as well as particle’s location near substrate are obtained from a computational fluid dynamics (CFD) simulation of a radial suspension injection into a Metco-3MB plasma gun. Consequently, the trajectory of each particle upon the impact is calculated, to determine the final location of an impinged particle on the substrate or previously deposited particles. It is assumed that particles stick to impinged location based on prescribed scenarios. The coating structure is specified using a variable known as the “volume of fraction” defined as the volume of a computational cell occupied by the coating material. The numerical results can capture the columnar structures observed in SPS coatings by modeling the shadow effects.